STANDARDIZATION OF MILK AND CREAM I19 



0.8 : 160 : : 0.5 : 100. Hence 100 pounds of 3.2-per- 

 cent milk are required. 



IV (a) To obtain milk containing 3.5 per cent fat 

 from milk containing 3 . 2 per cent of fat by the addition of 

 milk containing 4-per-cent milk. 



Same formula as used in solving I. (a). 



I\'. (b) To obtain 160 pounds of milk containing 3.5 

 per cent of fat from milk containing 3.2 per cent of fat by 

 the addition of milk containing 4 per cent of fat. 



Same problem as in III. (b). 



Standardization of Cream. — The standardization of 

 cream is of still greater importance than, the standardiza- 

 tion of milk, because the variation of the percentage of 

 fat in cream is relatively greater than that of the milk. 

 The fat content of cream under normal conditions varies 

 between 10 per cent and 50 per cent, while that of milk 

 seldom varies over 2 per cent or 3 per cent. 



When a certain volume of cream is being sold, a com- 

 paratively larger amount of butter fat is disposed of than 

 when the same volume of milk is sold. As it is the butter 

 fat which is the most valuable part of cream and milk, 

 it is a good plan to regulate the price of cream according 

 to (i) the percentage of fat in the cream, (2) the current 

 price of the butter or butter fat. 



Even when the same separator is being used daily, the 

 percentage of fat in the cream is likely to vary as much as 

 5 per cent. This variation, if cream is not standardized, 

 may cause a considerable loss to either consumer or pro- 

 ducer. For instance, suppose 25 gallons of cream should 

 contain 20 per cent of fat, and it was unknowingly increased 

 to 25 per cent, there would than be 5 per cent more than 

 the standard required. If this cream were sold at 80 cents 

 a gallon, the price per pound of fat in the first case would 



